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Home >> Lexus >> 2017 >> GS 450h F Sport >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostic Codes (P0010 - P0193) >> SFI System >> DTC P0102: Mass or Volume Air Flow Circuit Low Input; DTC P0103: Mass or Volume Air Flow Circuit High Input [09/2014 - ] >> Procedure
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DTC P0102: Mass or Volume Air Flow Circuit Low Input; DTC P0103: Mass or Volume Air Flow Circuit High Input [09/2014 - ]: Procedure

  1. READ DTC OUTPUT 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
    5. Read the DTCs.

      Result

      Result Proceed to
      DTC P0102 is output A
      DTC P0103 is output B

    Result:  B

    B 

    See step  5

    Result:  A

    A 

    See step  2

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE VOLTAGE) 
    1. Disconnect the mass air flow meter connector.
      GTY533659Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Turn the power switch on (IG).
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      F39-3 (+B) - Body ground Power switch on (IG) 11 to 14 V
      TEXT IN ILLUSTRATION

      *a Front view of wire harness connector
      (to Mass Air Flow Meter)
    4. Reconnect the mass air flow meter connector.

    Result:  NG

    NG 

    See step  7

    Result:  OK

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
    1. Disconnect the mass air flow meter connector.
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      F39-5 (VG) - F5-98 (VG) Always Below 1 Ω
      F39-4 (E2G) - F5-130 (E2G) Always Below 1 Ω
      F39-5 (VG) or F5-98 (VG) - Body ground Always 10 kΩ or higher
    4. Reconnect the mass air flow meter connector.
    5. Reconnect the ECM connector.

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - ECM) 

    Result:  OK

    OK 

    See step  4

  4. INSPECT MASS AIR FLOW METER 
    1. Perform On-vehicle Inspection (See service information). Refer to ON-VEHICLE INSPECTION [09/2014 - ] ).
    2. Perform Inspection (See service information). Refer to INSPECTION [09/2014 - ] ).
    3. Inspect the function of the mass air flow meter.
      1. Connect the Techstream to the DLC3.
      2. Turn the power switch on (IG).
      3. Turn the Techstream on.
      4. Put the engine in inspection mode (maintenance mode) (See service information). Refer to INSPECTION MODE PROCEDURE [09/2014 - 10/2015] Refer to INSPECTION MODE PROCEDURE [10/2015 - ] ).
      5. Start the engine.
      6. Enter the following menus: Powertrain / Engine and ECT / Data List / MAF.
      7. Check that the reading of the MAF value changes when the engine is raced.

        OK

        The reading changes.

        HINT: 

        Perform "Inspection After Repair" after replacing the mass air flow meter (See service information). Refer to INITIALIZATION [09/2014 - ] ).

    Result:  OK

    OK 

    REPLACE ECM 

    (See service information). Refer to REMOVAL [09/2014 - ] )

    Result:  NG

    NG 

    REPLACE MASS AIR FLOW METER 

    (See service information). Refer to REMOVAL [09/2014 - ] )

  5. CHECK HARNESS AND CONNECTOR (SENSOR GROUND) 
    1. Disconnect the mass air flow meter connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      F39-4 (E2G) - Body ground Always Below 1 Ω
    3. Reconnect the mass air flow meter connector.

    Result:  OK

    OK 

    REPLACE MASS AIR FLOW METER 

    (See service information). Refer to REMOVAL [09/2014 - ] )

    Result:  NG

    NG 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - ECM) 
    1. Disconnect the mass air flow meter connector.
    2. Disconnect the ECM connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      F39-4 (E2G) - F5-130 (E2G) Always Below 1 Ω
    4. Reconnect the mass air flow meter connector.
    5. Reconnect the ECM connector.

    Result:  OK

    OK 

    REPLACE ECM 

    (See service information). Refer to REMOVAL [09/2014 - ] )

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - ECM) 

  7. CHECK HARNESS AND CONNECTOR (MASS AIR FLOW METER - NO. 1 INTEGRATION RELAY) 
    1. Disconnect the mass air flow meter connector.
    2. Remove the No. 1 integration relay from the No. 1 engine room relay block and junction block assembly.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      F39-3 (+B) - 1E-15 Always Below 1 Ω
      F39-3 (+B) or 1E-15 - Body ground Always 10 kΩ or higher

    Result:  OK

    OK 

    REPLACE NO. 1 INTEGRATION RELAY 

    Result:  NG

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (MASS AIR FLOW METER - NO. 1 INTEGRATION RELAY) 

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